{"id":996525,"date":"2024-12-27T09:15:47","date_gmt":"2024-12-27T01:15:47","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/996525.html"},"modified":"2024-12-27T09:15:50","modified_gmt":"2024-12-27T01:15:50","slug":"python-%e9%94%ae%e5%80%bc%e5%af%b9%e5%a6%82%e4%bd%95%e6%b7%bb%e5%8a%a0","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/996525.html","title":{"rendered":"python \u952e\u503c\u5bf9\u5982\u4f55\u6dfb\u52a0"},"content":{"rendered":"

\"python<\/p>\n

\u5f00\u5934\u6bb5\u843d\uff1a\u5728Python\u4e2d\u6dfb\u52a0\u952e\u503c\u5bf9\u7684\u64cd\u4f5c\u975e\u5e38\u7b80\u5355\uff0c\u4e3b\u8981\u65b9\u6cd5\u5305\u62ec\u4f7f\u7528\u5b57\u5178\u7684\u8d4b\u503c\u8bed\u6cd5\u3001\u4f7f\u7528update()\u65b9\u6cd5\u3001\u4f7f\u7528setdefault()\u65b9\u6cd5<\/strong>\u3002\u5176\u4e2d\uff0c\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u662f\u76f4\u63a5\u901a\u8fc7\u5b57\u5178\u8d4b\u503c\u8bed\u6cd5\u6765\u6dfb\u52a0\u952e\u503c\u5bf9\uff0c\u8fd9\u79cd\u65b9\u5f0f\u4e0d\u4ec5\u7b80\u6d01\u660e\u4e86\uff0c\u8fd8\u80fd\u5728\u5b57\u5178\u4e2d\u76f4\u63a5\u66f4\u65b0\u73b0\u6709\u7684\u952e\u503c\u5bf9\u3002\u4f8b\u5982\uff0c\u5f53\u4f60\u6709\u4e00\u4e2a\u5b57\u5178my_dict<\/code>\uff0c\u5e76\u5e0c\u671b\u6dfb\u52a0\u4e00\u4e2a\u952e\u4e3a'key1'<\/code>\u3001\u503c\u4e3a'value1'<\/code>\u7684\u952e\u503c\u5bf9\u65f6\uff0c\u53ea\u9700\u6267\u884cmy_dict['key1'] = 'value1'<\/code>\u5373\u53ef\u3002\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u8be6\u7ec6\u63a2\u8ba8\u8fd9\u51e0\u79cd\u65b9\u6cd5\u53ca\u5176\u5e94\u7528\u573a\u666f\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u4f7f\u7528\u5b57\u5178\u7684\u8d4b\u503c\u8bed\u6cd5<\/p>\n<\/p>\n

\u5728Python\u4e2d\uff0c\u5b57\u5178\u662f\u4e00\u79cd\u975e\u5e38\u7075\u6d3b\u7684\u6570\u636e\u7ed3\u6784\uff0c\u5141\u8bb8\u6211\u4eec\u901a\u8fc7\u7b80\u5355\u7684\u8d4b\u503c\u8bed\u6cd5\u6765\u6dfb\u52a0\u6216\u66f4\u65b0\u952e\u503c\u5bf9\u3002\u5f53\u4f60\u60f3\u8981\u5728\u5b57\u5178\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u65b0\u7684\u952e\u503c\u5bf9\u65f6\uff0c\u53ea\u9700\u8981\u5c06\u65b0\u952e\u4f5c\u4e3a\u7d22\u5f15\uff0c\u5e76\u4e3a\u5176\u5206\u914d\u4e00\u4e2a\u503c\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n

my_dict = {}<\/p>\n
my_dict['new_key'] = 'new_value'<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u7684\u597d\u5904\u662f\u7b80\u5355\u76f4\u63a5\uff0c\u65e0\u9700\u8c03\u7528\u989d\u5916\u7684\u65b9\u6cd5\u6216\u51fd\u6570\uff0c\u4fbf\u4e8e\u7406\u89e3\u548c\u4f7f\u7528\u3002\u6b64\u5916\uff0c\u5982\u679c\u952e\u5df2\u7ecf\u5b58\u5728\u4e8e\u5b57\u5178\u4e2d\uff0c\u8d4b\u503c\u64cd\u4f5c\u4f1a\u66f4\u65b0\u8be5\u952e\u5bf9\u5e94\u7684\u503c\u3002<\/p>\n<\/p>\n
\u7136\u800c\uff0c\u8fd9\u79cd\u65b9\u6cd5\u5728\u5904\u7406\u5927\u89c4\u6a21\u5b57\u5178\u6216\u9700\u8981\u6279\u91cf\u66f4\u65b0\u591a\u4e2a\u952e\u503c\u5bf9\u65f6\u53ef\u80fd\u663e\u5f97\u4e0d\u591f\u9ad8\u6548\uff0c\u56e0\u4e3a\u6bcf\u6b21\u53ea\u80fd\u6dfb\u52a0\u4e00\u4e2a\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
\u4e8c\u3001\u4f7f\u7528update()\u65b9\u6cd5<\/p>\n<\/p>\n
update()<\/code>\u65b9\u6cd5\u662fPython\u5b57\u5178\u63d0\u4f9b\u7684\u4e00\u4e2a\u975e\u5e38\u6709\u7528\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u7528\u4e8e\u540c\u65f6\u6dfb\u52a0\u6216\u66f4\u65b0\u591a\u4e2a\u952e\u503c\u5bf9\u3002\u8fd9\u4e2a\u65b9\u6cd5\u63a5\u53d7\u4e00\u4e2a\u5b57\u5178\u6216\u4e00\u4e2a\u5305\u542b\u952e\u503c\u5bf9\u7684\u53ef\u8fed\u4ee3\u5bf9\u8c61\u4f5c\u4e3a\u53c2\u6570\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1, 'b': 2}<\/p>\n
my_dict.update({'c': 3, 'd': 4})<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cupdate()<\/code>\u65b9\u6cd5\u4e0d\u4ec5\u53ef\u4ee5\u5411my_dict<\/code>\u5b57\u5178\u4e2d\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\uff0c\u8fd8\u53ef\u4ee5\u66f4\u65b0\u73b0\u6709\u7684\u952e\u503c\u5bf9\u3002\u5982\u679c\u4f20\u5165\u7684\u5b57\u5178\u4e2d\u5305\u542bmy_dict<\/code>\u4e2d\u5df2\u6709\u7684\u952e\uff0c\u90a3\u4e48\u8fd9\u4e9b\u952e\u7684\u503c\u5c06\u88ab\u66f4\u65b0\u3002<\/p>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u7279\u522b\u9002\u5408\u9700\u8981\u4e00\u6b21\u6027\u66f4\u65b0\u591a\u4e2a\u952e\u503c\u5bf9\u7684\u573a\u666f\uff0c\u63d0\u4f9b\u4e86\u5f88\u9ad8\u7684\u6548\u7387\u548c\u4fbf\u5229\u6027\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528setdefault()\u65b9\u6cd5<\/p>\n<\/p>\n
setdefault()<\/code>\u65b9\u6cd5\u662f\u4e00\u79cd\u8f83\u4e3a\u7279\u6b8a\u7684\u952e\u503c\u5bf9\u6dfb\u52a0\u65b9\u5f0f\uff0c\u5b83\u4e0d\u4ec5\u53ef\u4ee5\u7528\u4e8e\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\uff0c\u8fd8\u53ef\u4ee5\u7528\u4e8e\u5728\u4e0d\u6539\u53d8\u73b0\u6709\u503c\u7684\u60c5\u51b5\u4e0b\uff0c\u83b7\u53d6\u5b57\u5178\u4e2d\u7684\u503c\u3002\u5176\u8bed\u6cd5\u4e3a\uff1adict.setdefault(key, default=None)<\/code>\u3002\u5982\u679c\u952e\u4e0d\u5b58\u5728\uff0c\u5219\u5c06\u952e\u503c\u5bf9\u6dfb\u52a0\u5230\u5b57\u5178\u4e2d\uff0c\u503c\u4e3adefault<\/code>\uff1b\u5982\u679c\u952e\u5df2\u5b58\u5728\uff0c\u5219\u76f4\u63a5\u8fd4\u56de\u8be5\u952e\u5bf9\u5e94\u7684\u503c\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1}<\/p>\n
value = my_dict.setdefault('b', 2)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u7531\u4e8e\u952e'b'<\/code>\u4e0d\u5b58\u5728\uff0csetdefault()<\/code>\u65b9\u6cd5\u5c06\u952e\u503c\u5bf9'b': 2<\/code>\u6dfb\u52a0\u5230\u5b57\u5178\u4e2d\uff0c\u5e76\u8fd4\u56de\u503c2<\/code>\u3002<\/p>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u5728\u6dfb\u52a0\u952e\u503c\u5bf9\u7684\u540c\u65f6\u83b7\u53d6\u503c\u7684\u573a\u5408\uff0c\u7279\u522b\u662f\u5728\u5904\u7406\u9ed8\u8ba4\u503c\u6216\u521d\u59cb\u5316\u5b57\u5178\u4e2d\u7684\u5143\u7d20\u65f6\u975e\u5e38\u6709\u7528\u3002<\/p>\n<\/p>\n
\u56db\u3001\u4f7f\u7528\u5b57\u5178\u89e3\u5305\u8fd0\u7b97\u7b26<\/p>\n<\/p>\n
Python 3.5\u5f15\u5165\u4e86\u5b57\u5178\u89e3\u5305\u8fd0\u7b97\u7b26<\/code>\uff0c\u8fd9\u4e3a\u5408\u5e76\u4e24\u4e2a\u5b57\u5178\u63d0\u4f9b\u4e86\u4e00\u79cd\u7b80\u6d01\u7684\u65b9\u5f0f\uff0c\u4e5f\u53ef\u4ee5\u7528\u4e8e\u6dfb\u52a0\u952e\u503c\u5bf9\u3002\u901a\u8fc7\u5c06\u5305\u542b\u65b0\u952e\u503c\u5bf9\u7684\u5b57\u5178\u89e3\u5305\u5230\u539f\u5b57\u5178\u4e2d\uff0c\u4fbf\u53ef\u5b9e\u73b0\u952e\u503c\u5bf9\u7684\u6dfb\u52a0\u548c\u66f4\u65b0\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
my_dict = {'a': 1, 'b': 2}<\/p>\n
new_entries = {'c': 3, 'd': 4}<\/p>\n
my_dict = {<strong>my_dict, <\/strong>new_entries}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u5229\u7528\u4e86\u89e3\u5305\u7684\u7279\u6027\uff0c\u80fd\u591f\u5f88\u65b9\u4fbf\u5730\u5408\u5e76\u591a\u4e2a\u5b57\u5178\u3002\u7136\u800c\uff0c\u5b83\u5728\u5b57\u5178\u7279\u522b\u5927\u65f6\u53ef\u80fd\u4f1a\u5e26\u6765\u4e00\u4e9b\u6027\u80fd\u4e0a\u7684\u5f00\u9500\uff0c\u56e0\u4e3a\u5b83\u5b9e\u9645\u4e0a\u521b\u5efa\u4e86\u4e00\u4e2a\u65b0\u7684\u5b57\u5178\u3002<\/p>\n<\/p>\n
\u4e94\u3001\u4f7f\u7528collections\u6a21\u5757\u7684defaultdict<\/p>\n<\/p>\n
defaultdict<\/code>\u662fPython\u6807\u51c6\u5e93collections<\/code>\u6a21\u5757\u4e2d\u7684\u4e00\u4e2a\u7c7b\uff0c\u63d0\u4f9b\u4e86\u5b57\u5178\u7684\u6240\u6709\u529f\u80fd\uff0c\u5e76\u5141\u8bb8\u4e3a\u5b57\u5178\u4e2d\u7684\u952e\u63d0\u4f9b\u9ed8\u8ba4\u503c\u3002\u8fd9\u4f7f\u5f97\u5728\u5c1d\u8bd5\u8bbf\u95ee\u4e0d\u5b58\u5728\u7684\u952e\u65f6\uff0c\u53ef\u4ee5\u81ea\u52a8\u6dfb\u52a0\u4e00\u4e2a\u5177\u6709\u9ed8\u8ba4\u503c\u7684\u952e\u503c\u5bf9\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
from collections import defaultdict<\/p>\n
my_dict = defaultdict(int)<\/p>\n
my_dict['a'] += 1<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cdefaultdict<\/code>\u88ab\u521d\u59cb\u5316\u4e3a\u4e00\u4e2a\u6574\u6570\u7c7b\u578b\u7684\u5b57\u5178\uff0c\u56e0\u6b64\u6bcf\u4e2a\u4e0d\u5b58\u5728\u7684\u952e\u9ed8\u8ba4\u503c\u4e3a0\u3002\u901a\u8fc7my_dict['a'] += 1<\/code>\u64cd\u4f5c\uff0c\u952e'a'<\/code>\u88ab\u6dfb\u52a0\u5230\u5b57\u5178\u4e2d\uff0c\u5176\u503c\u4e3a1\u3002<\/p>\n<\/p>\n
\u8fd9\u79cd\u65b9\u6cd5\u5728\u9700\u8981\u9891\u7e41\u8bbf\u95ee\u548c\u4fee\u6539\u5b57\u5178\u4e2d\u7684\u952e\u65f6\u975e\u5e38\u6709\u7528\uff0c\u907f\u514d\u4e86\u624b\u52a8\u68c0\u67e5\u952e\u662f\u5426\u5b58\u5728\u7684\u9ebb\u70e6\u3002<\/p>\n<\/p>\n
\u516d\u3001\u4f7f\u7528\u5b57\u5178\u63a8\u5bfc\u5f0f<\/p>\n<\/p>\n
\u5b57\u5178\u63a8\u5bfc\u5f0f\uff08Dictionary Comprehension\uff09\u662f\u4e00\u79cd\u5728Python\u4e2d\u521b\u5efa\u5b57\u5178\u7684\u7b80\u6d01\u65b9\u6cd5\u3002\u901a\u8fc7\u5b57\u5178\u63a8\u5bfc\u5f0f\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u540c\u4e00\u8bed\u53e5\u4e2d\u5b9a\u4e49\u548c\u6dfb\u52a0\u591a\u4e2a\u952e\u503c\u5bf9\u3002\u4f8b\u5982\uff1a<\/p>\n<\/p>\n
keys = ['a', 'b', 'c']<\/p>\n
values = [1, 2, 3]<\/p>\n
my_dict = {k: v for k, v in zip(keys, values)}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5b57\u5178\u63a8\u5bfc\u5f0f\u975e\u5e38\u9002\u5408\u5728\u521b\u5efa\u5b57\u5178\u65f6\u6dfb\u52a0\u952e\u503c\u5bf9\u3002\u5b83\u63d0\u4f9b\u4e86\u7075\u6d3b\u6027\u548c\u53ef\u8bfb\u6027\uff0c\u7279\u522b\u662f\u5728\u9700\u8981\u6839\u636e\u67d0\u4e2a\u89c4\u5219\u6279\u91cf\u521b\u5efa\u952e\u503c\u5bf9\u65f6\u3002<\/p>\n<\/p>\n
\u603b\u7ed3\u800c\u8a00\uff0cPython\u63d0\u4f9b\u4e86\u591a\u79cd\u65b9\u6cd5\u6765\u6dfb\u52a0\u952e\u503c\u5bf9\uff0c\u6bcf\u79cd\u65b9\u6cd5\u90fd\u6709\u5176\u72ec\u7279\u7684\u4f18\u52bf\u548c\u9002\u7528\u573a\u666f\u3002\u6839\u636e\u5177\u4f53\u9700\u6c42\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u7801\u7684\u6548\u7387\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
 \u5982\u4f55\u5728Python\u4e2d\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\u5230\u5b57\u5178\u4e2d\uff1f<\/strong>
\u5728Python\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u8d4b\u503c\u8bed\u6cd5\u6765\u5411\u5b57\u5178\u4e2d\u6dfb\u52a0\u65b0\u7684\u952e\u503c\u5bf9\u3002\u53ea\u9700\u6307\u5b9a\u65b0\u7684\u952e\u5e76\u8d4b\u4e88\u5176\u76f8\u5e94\u7684\u503c\uff0c\u4f8b\u5982\uff1amy_dict['new_key'] = 'new_value'<\/code>\u3002\u8fd9\u6837\uff0c'new_key'<\/code>\u53ca\u5176\u5bf9\u5e94\u7684\u503c\u5c31\u4f1a\u88ab\u6dfb\u52a0\u5230\u5b57\u5178my_dict<\/code>\u4e2d\u3002<\/p>\n
Python\u5b57\u5178\u4e2d\u6dfb\u52a0\u952e\u503c\u5bf9\u65f6\u4f1a\u8986\u76d6\u5df2\u6709\u7684\u503c\u5417\uff1f<\/strong>
\u662f\u7684\uff0c\u5982\u679c\u5c1d\u8bd5\u6dfb\u52a0\u4e00\u4e2a\u5df2\u5b58\u5728\u7684\u952e\uff0c\u65b0\u7684\u503c\u5c06\u4f1a\u8986\u76d6\u65e7\u7684\u503c\u3002\u4f8b\u5982\uff0c\u5982\u679c\u5b57\u5178\u4e2d\u5df2\u7ecf\u6709\u952e'existing_key'<\/code>\uff0c\u6267\u884cmy_dict['existing_key'] = 'new_value'<\/code>\u5c06\u66ff\u6362\u6389\u539f\u6709\u7684\u503c\u3002<\/p>\n
\u5982\u4f55\u4f7f\u7528update()\u65b9\u6cd5\u5411\u5b57\u5178\u6dfb\u52a0\u591a\u4e2a\u952e\u503c\u5bf9\uff1f<\/strong>
\u53ef\u4ee5\u4f7f\u7528update()<\/code>\u65b9\u6cd5\u4e00\u6b21\u6027\u6dfb\u52a0\u591a\u4e2a\u952e\u503c\u5bf9\u3002\u4f20\u5165\u4e00\u4e2a\u5b57\u5178\u6216\u4ee5\u5143\u7ec4\u7684\u5f62\u5f0f\u63d0\u4f9b\u952e\u503c\u5bf9\u3002\u4f8b\u5982\uff1amy_dict.update({'key1': 'value1', 'key2': 'value2'})<\/code>\uff0c\u8fd9\u6837my_dict<\/code>\u5c06\u540c\u65f6\u6dfb\u52a0'key1'<\/code>\u548c'key2'<\/code>\u53ca\u5176\u5bf9\u5e94\u7684\u503c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u5f00\u5934\u6bb5\u843d\uff1a\u5728Python\u4e2d\u6dfb\u52a0\u952e\u503c\u5bf9\u7684\u64cd\u4f5c\u975e\u5e38\u7b80\u5355\uff0c\u4e3b\u8981\u65b9\u6cd5\u5305\u62ec\u4f7f\u7528\u5b57\u5178\u7684\u8d4b\u503c\u8bed\u6cd5\u3001\u4f7f\u7528update()\u65b9\u6cd5\u3001 […]","protected":false},"author":3,"featured_media":996540,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/996525"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=996525"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/996525\/revisions"}],"predecessor-version":[{"id":996543,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/996525\/revisions\/996543"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/996540"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=996525"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=996525"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=996525"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}